Eric Christopher e511c4b0df Temporarily Revert:
"[SLP] Generalization of stores vectorization."
 "[SLP] Fix -Wunused-variable. NFC"
 "[SLP] Vectorize jumbled stores."

As they're causing significant (10-30x) compile time regressions on
vectorizable code.

The primary cause of the compile-time regression is f228b5371647f471853c5fb3e6719823a42fe451.

This reverts commits:

f228b5371647f471853c5fb3e6719823a42fe451
5503455ccb3f5fcedced158332c016c8d3a7fa81
21d498c9c0f32dcab5bc89ac593aa813b533b43a
2019-11-06 16:06:15 -08:00
..
2019-11-06 16:06:15 -08:00